forked from mirrors/nixpkgs
25387a1bed
This command was useful when NixOS was spread across multiple repositories, but now it's pretty pointless (and obfuscates what happens, i.e. "git clone git://github.com/NixOS/nixpkgs.git").
100 lines
3.4 KiB
XML
100 lines
3.4 KiB
XML
<chapter xmlns="http://docbook.org/ns/docbook"
|
||
xmlns:xlink="http://www.w3.org/1999/xlink"
|
||
xmlns:xi="http://www.w3.org/2001/XInclude"
|
||
version="5.0"
|
||
xml:id="sec-getting-sources">
|
||
|
||
<title>Getting the Sources</title>
|
||
|
||
<para>By default, NixOS’s <command>nixos-rebuild</command> command
|
||
uses the NixOS and Nixpkgs sources provided by the
|
||
<literal>nixos-unstable</literal> channel (kept in
|
||
<filename>/nix/var/nix/profiles/per-user/root/channels/nixos</filename>).
|
||
To modify NixOS, however, you should check out the latest sources from
|
||
Git. This is as follows:
|
||
|
||
<screen>
|
||
$ git clone git://github.com/NixOS/nixpkgs.git
|
||
$ cd nixpkgs
|
||
$ git remote add channels git://github.com/NixOS/nixpkgs-channels.git
|
||
$ git remote update channels
|
||
</screen>
|
||
|
||
This will check out the latest Nixpkgs sources to
|
||
<filename>./nixpkgs</filename> the NixOS sources to
|
||
<filename>./nixpkgs/nixos</filename>. (The NixOS source tree lives in
|
||
a subdirectory of the Nixpkgs repository.) The remote
|
||
<literal>channels</literal> refers to a read-only repository that
|
||
tracks the Nixpkgs/NixOS channels (see <xref linkend="sec-upgrading"/>
|
||
for more information about channels). Thus, the Git branch
|
||
<literal>channels/nixos-14.12</literal> will contain the latest built
|
||
and tested version available in the <literal>nixos-14.12</literal>
|
||
channel.</para>
|
||
|
||
<para>It’s often inconvenient to develop directly on the master
|
||
branch, since if somebody has just committed (say) a change to GCC,
|
||
then the binary cache may not have caught up yet and you’ll have to
|
||
rebuild everything from source. So you may want to create a local
|
||
branch based on your current NixOS version:
|
||
|
||
<screen>
|
||
$ nixos-version
|
||
14.04.273.ea1952b (Baboon)
|
||
|
||
$ git checkout -b local ea1952b
|
||
</screen>
|
||
|
||
Or, to base your local branch on the latest version available in a
|
||
NixOS channel:
|
||
|
||
<screen>
|
||
$ git remote update channels
|
||
$ git checkout -b local channels/nixos-14.12
|
||
</screen>
|
||
|
||
(Replace <literal>nixos-14.12</literal> with the name of the channel
|
||
you want to use.) You can use <command>git merge</command> or
|
||
<command>git rebase</command> to keep your local branch in sync with
|
||
the channel, e.g.
|
||
|
||
<screen>
|
||
$ git remote update channels
|
||
$ git merge channels/nixos-14.12
|
||
</screen>
|
||
|
||
You can use <command>git cherry-pick</command> to copy commits from
|
||
your local branch to the upstream branch.</para>
|
||
|
||
<para>If you want to rebuild your system using your (modified)
|
||
sources, you need to tell <command>nixos-rebuild</command> about them
|
||
using the <option>-I</option> flag:
|
||
|
||
<screen>
|
||
$ nixos-rebuild switch -I nixpkgs=<replaceable>/my/sources</replaceable>/nixpkgs
|
||
</screen>
|
||
|
||
</para>
|
||
|
||
<para>If you want <command>nix-env</command> to use the expressions in
|
||
<replaceable>/my/sources</replaceable>, use <command>nix-env -f
|
||
<replaceable>/my/sources</replaceable>/nixpkgs</command>, or change
|
||
the default by adding a symlink in
|
||
<filename>~/.nix-defexpr</filename>:
|
||
|
||
<screen>
|
||
$ ln -s <replaceable>/my/sources</replaceable>/nixpkgs ~/.nix-defexpr/nixpkgs
|
||
</screen>
|
||
|
||
You may want to delete the symlink
|
||
<filename>~/.nix-defexpr/channels_root</filename> to prevent root’s
|
||
NixOS channel from clashing with your own tree.</para>
|
||
|
||
<!-- FIXME: not sure what this means.
|
||
<para>You should not pass the base directory
|
||
<filename><replaceable>/my/sources</replaceable></filename>
|
||
to <command>nix-env</command>, as it will break after interpreting expressions
|
||
in <filename>nixos/</filename> as packages.</para>
|
||
-->
|
||
|
||
</chapter>
|